This invention relates to newly identified polynucleotides, polypeptides encoded by them and to the use of such polynucleotides and polypeptides, and to their production. More particularly, the polynucleotides and polypeptides of the present invention relate to CSBP/p38 MAP Kinases family, hereinafter referred to as p38beta2. The invention also relates to inhibiting or activating the action of such polynucleotides and polypeptides.
Cytokines play an important role in regulating the cellular response during inflammation and other immune functions. Of particular interest are the cytokines interleukin-1 (IL-1, xcex1 and xcex2) and tumor necrosis factor (TNF, xcex1 and xcex2), which are the intercellular proteins involved in the initial step of the inflammatory response cascade (Arai, et al., Ann. Rev. Biochem 59: 783-836 (1990)). Thus, there has been a substantial amount of research recently devoted to interfering with the production of IL-1 and TNF in response to an inflammatory stimulus.
One therapeutic approach involves suppressing the production of IL-1 and TNF at the level of transcription and/or translation and/or secretion. The activities associated with certain of pyridinyl imidazoles led to a class of compounds referred to as xe2x80x9cCSAIDsxe2x80x9d, or Cytokine Suppressing Anti-Inflammatory Drugs. These compounds appear to arrest the expression of IL-1 and TNF predominantly at the translational level, although a lesser effect on transcription has also been observed but effects on other steps cannot be ruled out.
The pyridinyl imidazole, 5-(4-pyridyl)-6(4-fluorophenyl)-2,3-dihydrouimdazo(2,1-b)thiazole (SKandF 86002) was identified as the prototypic CSAID. The basis for its activity has been established and characterized (Lee, et al., Int""l. J. Immunopharm. 10(7): 835-843 (1988); Agents and Actions 27(3/4): 277-279 (1989) and Int""l. J. Immunother. 6(l):1-12 (1990)). SAR studies suggest that cytokine suppressive effect of the pyridinyl imidazoles represents a unique activity independent of their inhibitory effects on eicosanoid and leukotriene production.
Since the CSAIDs have substantial potential as novel anti-inflammatory therapeutic agents, there is significant interest in characterizing their mechanism of action at the molecular level, as well as obtaining compounds with increased selectivity and potency. Specifically, identification and characterization of the CSAID molecular target would enhance the understanding of the biochemical processes involved in inflammation and aid in the design and screening of more potent anti-inflammatory drugs. This invention discloses, inter alia, the purification and characterization of additional CSAID binding proteins (CSBPs).
p38beta2 is a member of the CSBP/p38 MAP kinase family (Cytokine Suppressive Anti-inflammatory Drug (CSAID) binding protein family) of serine-threonine protein kinases (Marshall, C. J. (1994) Curr. Opinion Genet. Develop. 4, 82-89). Members of the MAP kinase family are characterized by having a xe2x80x9cTxYxe2x80x9d amino acid motif (T=Threonine, Y=tyrosine and X is any amino acid) in an activation loop near to the active site. Phosphorylation of both the tyrosine and threonine by a MAP kinase kinase in response to an appropriate stimulus is required for the activation of MAP kinase activity. There are three families of MAP kinases which are distinguished by the nature of the xe2x80x9cxxe2x80x9d amino acid and the size of the activation loop (Cano, E., and Mahadevan, L. C. (1995) Trends Biochem. Sci. 20, 117-122). Hence, the erks have TEY, JNK/SAPKs have TPY and the CSBP/p38s have TGY. These differences reflect differences in the activating MAP kinase kinases and in the cellular stimuli which activate each MAP kinase. Within each family, the activating stimuli appear to be very similar. Thus the erks respond mostly to mitogenic stimuli (e.g., EGF, PDGF), while the JNK/SAPKs and CSBP/p38s respond to several cellular stresses (eg UV, osmotic, heat or chemical stress, hypoxia, oxidants etc) and proinflammatory stimuli (e.g., LPS, IL-1, TNF, etc.).
Recently, several new forms of P38 have been identified. In addition to the two splice variants of P38, CSBP1 and CSBP2, a further spliced variant was identified through a yeast two-hybrid interaction screen with the nuclear protein Max (Zervos, A. S., Faccio, L., Gatto, J. P., Kyriakis, J. M., and Brent, R. (1995) Proc. Natl. Acad. Sci. USA 92, 10531-10534). Two homologues with significant amino acid identity which also retain the xe2x80x9cTGYxe2x80x9d motif characteristic of the P38 family were also recently identified: p38beta (Jiang, Y., Chen, C., Li, Z., Guo, W., Gegner, J. A., Lin, S., and Han, J. (1996) J. Biol. Chem. 271, 17920-17926), and ERK6/SAPK3 (Lechner, C., Zahalka, M. A., Giot, J. F., Moller, N. P. H., and Ullrich, A. (1996) Proc. Natl. Acad. Sci. USA 93, 4355-4359;Goedert et al. xe2x80x9cActivation of the novel stress-activated protein kinase SAPK4 by cytokines and cellular stresses is mediated by SKK3 (MKK6); comparison of its substrate specificity with that of other SAP kinasesxe2x80x9d, EMBO Journal, Vol. 16, No. 12, pp. 3563-3571 (1997). This indicates that these CSBP/p38 MAP Kinases have an established, proven history as therapeutic targets. Clearly there is a need for identification and characterization of further members of CSBP/p38 MAP Kinases family which can play a role in preventing, ameliorating or correcting dysfunctions or diseases, including, but not limited to, central nervous system disorder such as senile dementia of the Alzheimer""s type (SDAT), mutiple sclerosis, cerebral malaria, stroke, head trauma and spinal cord injury; cardiovascular diseases such as restenosis and atherosclerosis; inflammatory diseases such as Adult Respiratory Disease Syndrome (ARDS), Rheumatoid arthritis, Osteoarthritis, Inflammatory Bowel Disease (IBD), psoriasis, dermatitis, asthma; and other such diseases or conditions associated with dysregulated or excess cytokines such as osteoporosis, sepsis due to surgical or traumatic incident, chronic renal failure, AIDs, cachexia and autoimmune conditions such as lupus erthyromatosis, host graft rejection and graft verus host disease.
In one aspect, the invention relates to p38beta2 polypeptides and recombinant materials and methods for their production. Another aspect of the invention relates to methods for using such p38beta2 polypeptides and polynucleotides. Such uses include the treatment of central nervous system disorder such as senile dementia of the Alzheimer""s type (SDAT), mutiple sclerosis, cerebral nalaria, stroke, head trauma and spinal cord injury; cardiovascular diseases such as restenosis and atherosclerosis; inflammatory diseases such as Adult Respiratory Disease Syndrome (ARDS), Rheumatoid arthritis, Osteoarthritis, Inflammatory Bowel Disease (IBD), psoriasis, dermatitis, asthma; and other such diseases or conditions associated with dysregulated or excess cytokines such as osteoporosis, sepsis due to surgical or traumatic incident, chronic renal failure, AIDs, cachexia and autoimmune conditions such as lupus erthyromatosis, host graft rejection and graft verus host disease, among others. In still another aspect, the invention relates to methods to identify agonists and antagonists using the materials provided by the invention, and treating conditions associated with p38beta2 imbalance with the identified compounds. Yet another aspect of the invention relates to diagnostic assays for detecting diseases associated with inappropriate p38beta2 activity or levels.